JPH029738B2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Technical Field of the Invention The present invention relates to a parallel redundancy system for an oscillation device for bidirectional bus transmission, and in particular, it minimizes disturbances in a bidirectional common bus and improves oscillation. The present invention relates to an oscillation device that can prevent burnout of a line driver of an apparatus.

(2) Prior art In inverter devices used as uninterruptible power supplies, multiple inverter devices are connected in parallel for the purpose of improving system reliability. It has become common practice to disconnect the inverter from the parallel bus and use another healthy inverter to supply stable power to the load. In order to control the parallel operation of the inverter devices, a common reference pulse is required for each inverter device.

This reference pulse is obtained from a common oscillator for all inverter devices connected in parallel, or from an oscillator provided individually for each inverter device, and the sending and receiving of the reference pulse from this oscillator is the main function of the parallel operation system. This is one of the factors that determines reliability.

An example of an oscillator method in such a parallel operation system will be explained based on FIG. 1. In FIG. 1, 11, 21 are inverter devices, 12, 2
2 is the output, 13, 23 is the input during parallel operation,
30 is a parallel bus, 31 is a load, 41 is a reference pulse signal, and 51 is a redundant oscillator. The output of the redundant oscillator 51 is sent to each reference pulse signal 41 to the inverter devices 11 and 21.
The voltage phase of the outputs 12, 22 of the inverter devices 11, 21 is determined. The redundant oscillator 51 is well known, and an example thereof is shown in FIG. In FIG. 2, parts having the same functions as those in FIG. 1 are given the same numbers. In FIG. 2, 42 is a bidirectional common bus, 61 is a reference oscillator, 62 is a synchronized oscillator, 63 is a line driver, 65 is a line receiver, and 651 is a synchronization signal for the synchronized oscillator 62. The synchronized oscillator 62 is an oscillator whose oscillation frequency is set lower than the oscillation frequency of the reference oscillator 61 with high frequency accuracy, and which operates at its own frequency even if the reference oscillator 61 should fail. Moreover, the circuit is constructed of a simple and highly reliable circuit that utilizes relaxation oscillation of a unidirectional transistor.

Next, the operation will be briefly explained. The output of the reference oscillator 61 is transmitted to a synchronized oscillator 62 and a line driver 63.
It is output to the common bus 42 via. Furthermore, if the synchronization signal 651 of the synchronized oscillator 62 is obtained from the common bus 42 via the line receiver 65, the synchronized oscillator 62 has the highest operating frequency among the reference oscillator 61 and other oscillators connected to the common bus 42. It is synchronized with a higher oscillator, and even if its output pulse is cut off, operation continues in synchronization with another healthy reference oscillator 61 with the next highest operating frequency.

Next, FIG. 3 shows an example of a combination of the line driver 63 and line receiver 65 shown in FIG. 2. Components with the same symbols as those in FIGS. 1 and 2 have the same functions; 631 is the input signal of the line driver 63 corresponding to the output of the synchronized oscillator 62; 632, 63
3 is a resistor, 634 is a transistor, 635, 65
3 is a pulse transformer, 652 is a diode, Vcc
is the power supply and COM is the ground potential. When a pulse of "1" is applied to the input signal 631 of the line driver 63, the transistor 634 turns on, the pulse transformer 635 is excited, and the common bus 42
A synchronizing signal 651 corresponding to the output of the line receiver 65 is output. Also line driver 63
Even if the input signal 631 of the synchronized oscillator 63 is "0", a pulse output from another oscillator connected to the common bus 42 is given as the synchronization signal 651 of the synchronized oscillator 62 via the pulse transformer 653.

(3) Problems with the prior art In the method shown in FIG. 2, the number of wires for transmitting and receiving the reference pulse signal 41 can be minimized by using the common bus method, and the reliability can be increased. , when the input signal 631 of the line driver 63 of one oscillator becomes "1" for a predetermined period of time or more, the pulse transformer 635 becomes saturated and the transistor 634 is burnt out, and the common bus 42 becomes short-circuited, causing parallel operation. It becomes impossible to send and receive the reference pulse 41 of the system, and a cross current flows between parallel devices, leading to a system failure. If the transistor 634 becomes defective and short-circuited, the system of the line driver 63 shown in FIG. 3 will lead to a system failure, but in order to solve this problem, the system of the line driver 63 shown in FIG. 4 can be used. Figure 4, 3rd
Components with the same functions as those in the figure are given the same reference numerals.
Further, 636 and 637 are resistors, and 638 is a transistor. In the device shown in FIG. 4, two transistors are connected in series, which reduces the probability that two transistors will fail at the same time and cause both to become short-circuited, thereby increasing reliability.

However, even with the method shown in FIG. 4, it is possible that both transistors may be damaged, and even in this case, a system failure is inevitable.

(4) Purpose of the Invention The present invention has been made to solve the above-mentioned drawbacks of the conventional technology. The oscillation device that detected the abnormality is immediately disconnected from the bidirectional common bus to minimize disturbance to the common bus and to prevent burnout of the line driver of the oscillation device. The purpose of the present invention is to provide an oscillation device that achieves this.

(5) Structure of the Invention In order to achieve the above object, the present invention configures a line driver of an oscillation device to send pulses to an output line by cooperative operation of a plurality of active elements connected in series, and The line driver is characterized by having a pulse width abnormality detection circuit that detects that any one of the plurality of active elements in the line driver is in an ON state for a predetermined period of time or more, and stops the operation of each of the plurality of active elements. be.

(6) Embodiment of the invention An embodiment of the invention will be described below based on the drawings. In FIG. 5, the same symbols as in FIG. 2 indicate the same functions, 66 is a pulse detection signal, 67 is a pulse width abnormality detection circuit, and 70 is a line driver 6.
3 shows the stop command.

In the present invention, the line driver 63 is provided with a pulse width abnormality detection circuit 67, and when an abnormality is detected, a stop command is given to the line driver 63, thereby stopping the line driver 63.

FIG. 6 shows an example of the configuration of this pulse width abnormality detection circuit 67, and FIG. 7 shows its operation. FIG. 6 shows that two transistors 634 and 638 connected in series are provided in the line driver as shown in FIG.
This is an example in which an output pulse is generated by the cooperative operation of 34 and 638, and parts having the same functions as those in FIG. 4 are given the same reference numerals.

In the figure, 671 to 674 are resistors, 675 and 676
is a photocoupler, 677 and 678 are pulse width detection signals, 679 to 681 are NOT circuits, and 682 is a
AND circuit, 683 is its output, 684 is a digital counter, output 683 of AND circuit 682
688 is a flip-flop; 688 is a flip-flop;
687 is its reset signal, 689 is a sequence signal such as display, 690 is a NOT circuit, 701 and 70
2 is a diode.

To explain this operation based on FIG. 7, t ₀ represents the normal pulse width of the reference pulse signal 41, and t ₁ represents the count-out time of the digital counter 684. Here, the countout time t ₁ of the digital counter 684 is the time when the transistors 634 and 638 are
The time is set so that even in the ON state, the pulse transformer 635 is saturated and damage does not occur.

In the case of FIG. 7A, if an abnormality occurs in the input signal 631 of the line driver 63 and the input signal 631 remains "1", then the NOT circuit 681
output becomes “0” and output 6 of AND circuit 682
83, the digital counter 684 measures the predetermined time t ₁
After counting out, the output 686 operates the flip-flop 688, and the NOT circuit 6
By setting the bases of the transistors 634 and 638 to "0" through the line driver 63
to stop. In this case, two transistors 63
4,638 are both stopped, so even if one transistor fails at this point, the line driver 63 can be stopped by the other healthy transistor, which ensures the reliability of abnormal stop operation. is high. In the case of FIG. 7B, if the transistors 634 and 638 are normal, a voltage is constantly applied to the photocoupler 675 and a voltage is applied to the photocoupler 676 for a period T ₁ -pulse width t ₀ , so that the digital counter 684 will not count out, but if transistor 634 is damaged and shorted, no voltage will be applied to photocoupler 675, and digital counter 684 will not count out.
counts out after a predetermined time _t1 , operates flip-flop 688, and transistors 634,
The base of the transistor 638 is set to "0", and the line driver 63 is stopped by the healthy transistor 638. Furthermore, if the transistor 638 becomes short-circuited, this is detected by the photocoupler 676, and the operation is stopped by the other healthy transistor 634 in the same manner as described above. In this way, if either one of the two transistors 634, 638 fails, it is detected and the remaining healthy transistor is stopped, so the probability that the two transistors will be shorted at the same time is greatly reduced. Therefore, disturbance of the common bus 42 due to simultaneous short circuits is prevented.

Here, if the countout time t ₁ is brought closer to t ₀ , the protection operation after the line driver 63 becomes abnormal becomes faster and more reliable. Also,
Clock pulse 685 of digital counter 684
If the operating frequency of the digital counter is increased, the precision of the counting operation of the digital counter will be increased.

With the above configuration, if the redundant oscillator 51 is operating without abnormality in FIG. 5, all the inverter devices in the parallel operation system are operated with the same phase reference 64. Should line driver 6
3, the pulse width abnormality detection circuit 67
detects an abnormality and the redundant oscillator 51 that has caused the abnormality
and immediately disconnect from the common bus 42.

(7) Effects of the Invention As explained above, according to the present invention, an abnormality in the oscillator caused by the line driver of the oscillator is detected, and only the oscillator in which the abnormality has been detected can be operated bidirectionally without stopping the inverter device. common bus 4
2, it is possible to minimize disturbances in the common bus 42, and to prevent burnout of transistors due to saturation of the pulse transformer of the line driver of the oscillator. In particular, the line driver is configured to output pulses through the joint operation of a plurality of active elements connected in series, and each of the active elements is stopped when an abnormality is detected in the active element.
Even if some active elements are short-circuited due to damage, the line driver can be reliably stopped using other healthy active elements, and common bus disturbances due to simultaneous short-circuiting of all active elements can be prevented. This effect can be obtained.

[Brief explanation of drawings]

Figure 1 is a block diagram of a conventional example of an individual redundant oscillator control method in a parallel operation system, Figure 2 is a circuit diagram showing a specific example of an individual redundant oscillator, and Figure 3 is a block diagram of a conventional example of an individual redundant oscillator control method in a parallel operation system.
The figure is a circuit diagram showing a conventional example of a line driver.
The figure is a circuit diagram showing another conventional example of a line driver.
FIG. 5 is a block diagram showing one embodiment of the present invention, FIG. 6 is a circuit diagram showing a specific embodiment of the pulse width abnormality detection circuit, and FIG. 7 is a time chart showing the operation of FIG. 6. be. 11, 21... Inverter device, 12, 22...
...Output, 13, 23...High speed disconnector, 30...
Parallel bus, 31...Load, 41...Reference pulse signal, 42...Common bus, 51...Individual redundant oscillator, 61...Reference oscillator, 62...Synchronized oscillator, 63...Line driver, 65...Line Receiver, 651...Synchronization signal, 631...Input signal, 632, 633, 636, 637...Resistance,
634, 638...Transistor, 652...Diode, 66...Pulse detection signal, 67...Pulse width abnormality detection signal, 70...Stop command, 67
1,672,673,674...Resistance, 675,
676...Photocoupler, 677,678...Pulse width detection signal, 679,680,681,69
0...NOT circuit, 682...AND circuit, 68
3,686...Output, 684...Digital counter, 685...Clock pulse, 687...Reset signal, 688...Flip-flop, 689
...Sequence signal, 701, 702...Diode.

Claims (1)

[Claims] 1. A reference oscillator, a line driver that operates in response to the output of the reference oscillator or the output of a synchronized oscillator that oscillates in synchronization with other synchronization signals, and sends pulses to the output line, and an output line. and a line receiver that receives the signal and supplies the other synchronization signal to the synchronized oscillator, and
Connect the output lines of each oscillator with a common signal line, and
In the parallel redundant type oscillator for bidirectional common bus transmission in which synchronized oscillators in other oscillators are synchronized by pulses sent from one oscillator onto the common signal line, the line driver is configured to The pulse is generated by the cooperative operation of a plurality of series-connected active elements that operate in response to the output of a synchronous oscillator, and any one of the plurality of active elements in the line driver is in an ON state for a predetermined period of time or more. An oscillation device comprising: a pulse width abnormality detection circuit that detects that this occurs and stops each of the plurality of active elements regardless of the output of the reference oscillator or the output of the synchronized oscillator. 2. The oscillation device according to claim 1, wherein the pulse width abnormality detection circuit includes a digital counter that counts clock pulses while any of the active elements in the line driver is in an ON state.